Friction
Physics · 50 practice questions
Static and dynamic friction; coefficient of limiting friction and its determination; advantages and disadvantages of friction and ways to reduce it; qualitative treatment of viscosity and terminal velocity; Stoke's law.
- Differentiate between static and dynamic friction.
- Determine the coefficient of limiting friction.
- Compare the advantages and disadvantages of friction and suggest ways to reduce it.
- Analyse factors affecting viscosity and terminal velocity, and apply Stoke's law.
Try a few questions
- Practice question 1
Air resistance increases with an object's speed, which is why a skydiver's terminal velocity is reached only after their speed has increased sufficiently for drag to
- A.exceed their weight significantly
- B.become completely negligible compared to their weight
- C.reverse the direction of their fall entirely
- D.balance their weight
Show the answer
D. balance their weight
Terminal velocity is reached precisely when the growing air resistance exactly balances the constant downward weight.
- Practice question 2
A raindrop falling through air reaches terminal velocity when its weight is exactly balanced by
- A.the force of gravity alone, with no other force involved
- B.an equal and opposite raindrop falling nearby
- C.the combined forces of air resistance and upthrust acting on it
- D.the surface tension of the raindrop itself
Show the answer
C. the combined forces of air resistance and upthrust acting on it
At terminal velocity, these upward resistive forces together match the downward weight, giving zero net force.
- Practice question 3
Lubricants, such as oil or grease, reduce friction mainly by
- A.increasing the roughness of the two contacting surfaces
- B.increasing the normal reaction force between the two surfaces
- C.permanently bonding the two contacting surfaces together
- D.keeping two solid surfaces from making direct contact, letting them slide over a thin fluid layer
Show the answer
D. keeping two solid surfaces from making direct contact, letting them slide over a thin fluid layer
A lubricant's thin fluid film replaces direct solid-solid contact, greatly reducing the resulting friction.
More UTME Physics topics
Practise with instant feedback
Answer questions one at a time and see the right answer and the reason straight away. Free to start.
Start practising